| Self-driving micro/nano motor is a micro/nano scale machine,which can convert chemical energy,thermal energy and other energy in the surrounding environment into kinetic energy to realize self propulsion.These micro and nano machines have the ability to perform some key tasks in an autonomous,targeted and selective way,and have many application prospects in cancer diagnosis,drug targeted transportation,water quality repair,etc.In this paper,mesoscopic simulation method is used to do two parts of the research.One part discusses the properties of spot microchannels as chemical chips to control the directional motion of micro/nano motors.The other part discusses the dynamic characteristics of micro/nano motor in the active environment of periodic oscillation.At present,the research on the micro-nano motor is mainly to prepare various types of active particles and explore their dynamic behavior.For example,the self propulsion motion of the cash platinum micro rod,gold nickel micro rod and Janus particles in the aqueous solution of hydrogen peroxide has been realized in the experiment,but limited to the small size of the motor and the strong fluctuation behavior of the environment,there are some difficulties in the fine research of the experiment Hard.In the simulation,we can study the dynamic properties of the motor in various complex environments,such as the influence of obstacles,potential wells and activation degree on the motor aggregation.In the first chapter of this paper,the development and research of self driving motor are introduced briefly.The second chapter introduces the numerical simulation method and basic particle model used in this paper: it is a dynamic model of self driving spherical dimer motor by chemical reaction,which is established by combining molecular dynamics(MD)and multiparticle collision dynamics(MPC).In our model,the solution particles are dominant.In the third chapter,we use MD-MPC simulation method to construct the chemical pattern chip,and study the properties of using the pattern chip to control the directional transport of micro/nano motor.In this chapter,we introduce and study the control of active substances by the activated spot environment.The patterned microchip device consists of chemical banded channels filled with fuel particles.These channels can be realized by chemical surface reaction of spatiotemporal patterned in experiments.By establishing the transmission dynamics model of the nano dimer motor in the microchannel,we studied the influence of different dimer motor volume fraction and radius on the transport effect of the motor.The results showed that the increase of dimer motor volume fraction and radius reduced the first cruise time of the motor(the time when the first motor reaches the end point),but the mechanism was different: volume fraction shadow The probability of contact and entry into the microchannel depends on the radius of the chemical channel.The results show that the transport efficiency of the motor is more easily affected by the particle size.In the fourth chapter,the MD-MPC method is used to simulate the dynamics of micromotors in an active environment with periodic oscillations.Due to the interaction of concentration gradient and hydrodynamic coupling with motors,the collective motion of these motors is greatly affected by the oscillation characteristics of the environment.The dynamic model of the spherical nano dimer motor in the oscillating medium is established and the numerical simulation is carried out.The results show how the periodic oscillation of the chemical concentration in the environment causes the periodic dispersion and aggregation of the motor clusters.In this chapter,the dynamic process of motor cluster formation,the periodic change of propulsion and diffusion behavior,and the structure of instantaneous cluster formation are analyzed.The relationship between the transformation rate of motor cluster aggregation and the oscillation frequency of dimer motor density and the change of chemical concentration in the environment is given in the phase diagram.The results of this research can provide some reference and help for the design of microfluidic integrated devices for transmitting micro-nanoscale objects,and contribute to the self-assembly of dimer motors in complex active media. |
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